Rename RVM gemset to match repository name

Change-Id: If505dc8a5ae1f09fce8e5352e64e4afa81090f5e
Use Ruby 1.9.3p374 locally

Cloudbees does not support it yet.

Change-Id: I8c5a67b7f34ec265fe3af39df0fa25cfa3721a4c
Update Ruby gems

Change-Id: Ie5936486b3d66e95127d39d655710f4b1ad7deb5
Update Firefox to version 18

Change-Id: Ibc5518a9e245af62e173a9002abedce80cf007a6
Merge changes Ibc5518a9,Ie5936486,I8c5a67b7,If505dc8a

* changes:
  Update Firefox to version 18
  Update Ruby gems
  Use Ruby 1.9.3p374 locally
  Rename RVM gemset to match repository name